1903 Submissions

[5] viXra:1903.0568 [pdf] submitted on 2019-03-31 14:06:17

Nullspace and Mitigation in Seismic Imaging and Seismic Inversion

Authors: August Lau, Alfonso Gonzalez
Comments: 14 Pages.

Seismic inversion is the inverse problem in seismic data processing. Seismic inversion is normally used to recover the medium properties or reflectivity series given the input seismic traces. Nullspace is common in linearized inversion where many vectors could be mapped into the one vector. It is an indication that many models could fit the same data, regardless of the inversion method. Inversion could give odd geometric shapes that are not physical or geological. We will discuss mitigation of nullspace to yield results that are meaningful for interpretation of geologic layers for oil and gas exploration.
Category: Geophysics

[4] viXra:1903.0323 [pdf] submitted on 2019-03-17 09:56:44

Proven Methods for Filtering SG Data

Authors: Herbert Weidner
Comments: 5 Pages.

Subject are different methods for noise-free data reduction of low-frequency geophysical data and identification of interference sources. The most important method is the selective compensation of strong spectral lines.
Category: Geophysics

[3] viXra:1903.0129 [pdf] submitted on 2019-03-07 09:44:20

Non-Parametric Wavelet Functional Analysis for Horizontal and Vertical Displacements Derived from GPS Stations in Western Alaska During the Year 2012

Authors: Homayoon Zahmatkesh, Abbas Abedini
Comments: 19 Pages. Earth Science Research; Vol. 6, No. 2; 2017

In order to analyze the dynamic processes of the Earth interior and the effect of the propagation of the seismic waves to the surface, a comprehensive study of the Earth crust kinematics is necessary. Although the Global Positing System (GPS) is a powerful method to measure ground displacements and velocities both horizontally and vertically as well as to infer the tectonic stress regime generated by the subsurface processes (from local fault systems to huge tectonic plate movements and active volcanoes), the complexity of the deformation pattern generated during such movements is not always easy to be interpreted. Therefore, it is necessary to work on new methodologies and modifying the previous approaches in order to improve the current methods and better understand the crustal movements. In this paper, we focus on western Alaska area, where many complex faults and active volcanoes exist. In particular, we analyze the data acquired each 30 seconds by three GPS stations located in western Alaska (AC31, AB09 d AB11) from January 1, 2012 to December 31, 2012 in order to compute their displacements in horizontal and vertical components by vectorial summation of the average daily and annual velocities components. Furthermore, we design non-parametric DMeyer and Haar wavelets for horizontal and vertical velocities directions in order to identify significant and homogenous displacements during the year 2012. Finally, the non-parametric decomposition of total horizontal and vertical normalized velocities based on level 1 and level 2 coefficients have been applied to compute normal and cumulative probability histograms related to the accuracy and statistical evolution of each applied wavelet. The results present a very good agreement between the designed non-parametric wavelets and their decomposition functions for each of the three above mentioned GPS stations displacements and velocities during the year 2012.
Category: Geophysics

[2] viXra:1903.0116 [pdf] submitted on 2019-03-06 06:43:04

A Peculiar Natural Resonance of the Earth at 46.265 µHz

Authors: Herbert Weidner
Comments: 6 Pages.

By carefully choosing the filter methods, the noise level of geophysical data could be reduced sufficiently to detect a hitherto unknown spectral line whose modulation is phase-locked to the duration of the year. The origin is enigmatic.
Category: Geophysics

[1] viXra:1903.0040 [pdf] submitted on 2019-03-02 07:06:21

On the True Shape of the Earth

Authors: Royan Rosche
Comments: 1 Page.

I show why the Earth does not have a geometric shape
Category: Geophysics